/* ----------------------------------------------------------------------
* Copyright (C) 2010 ARM Limited. All rights reserved.
*
* $Date:        15. February 2012
* $Revision: 	V1.1.0
*
* Project: 	    CMSIS DSP Library
* Title:		arm_cmplx_conj_q15.c
*
* Description:	Q15 complex conjugate.
*
* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
*
* Version 1.1.0 2012/02/15
*    Updated with more optimizations, bug fixes and minor API changes.
*
* Version 1.0.10 2011/7/15
*    Big Endian support added and Merged M0 and M3/M4 Source code.
*
* Version 1.0.3 2010/11/29
*    Re-organized the CMSIS folders and updated documentation.
*
* Version 1.0.2 2010/11/11
*    Documentation updated.
*
* Version 1.0.1 2010/10/05
*    Production release and review comments incorporated.
*
* Version 1.0.0 2010/09/20
*    Production release and review comments incorporated.
* ---------------------------------------------------------------------------- */

#include "arm_math.h"

/**
 * @ingroup groupCmplxMath
 */

/**
 * @addtogroup cmplx_conj
 * @{
 */

/**
 * @brief  Q15 complex conjugate.
 * @param  *pSrc points to the input vector
 * @param  *pDst points to the output vector
 * @param  numSamples number of complex samples in each vector
 * @return none.
 *
 * <b>Scaling and Overflow Behavior:</b>
 * \par
 * The function uses saturating arithmetic.
 * The Q15 value -1 (0x8000) will be saturated to the maximum allowable positive value 0x7FFF.
 */

void arm_cmplx_conj_q15(
    q15_t* pSrc,
    q15_t* pDst,
    uint32_t numSamples)
{

#ifndef ARM_MATH_CM0

	/* Run the below code for Cortex-M4 and Cortex-M3 */
	uint32_t blkCnt;                               /* loop counter */
	q31_t in1, in2, in3, in4;
	q31_t zero = 0;

	/*loop Unrolling */
	blkCnt = numSamples >> 2u;

	/* First part of the processing with loop unrolling.  Compute 4 outputs at a time.
	 ** a second loop below computes the remaining 1 to 3 samples. */
	while(blkCnt > 0u) {
		/* C[0]+jC[1] = A[0]+ j (-1) A[1] */
		/* Calculate Complex Conjugate and then store the results in the destination buffer. */
		in1 = *__SIMD32(pSrc)++;
		in2 = *__SIMD32(pSrc)++;
		in3 = *__SIMD32(pSrc)++;
		in4 = *__SIMD32(pSrc)++;

#ifndef ARM_MATH_BIG_ENDIAN

		in1 = __QASX(zero, in1);
		in2 = __QASX(zero, in2);
		in3 = __QASX(zero, in3);
		in4 = __QASX(zero, in4);

#else

		in1 = __QSAX(zero, in1);
		in2 = __QSAX(zero, in2);
		in3 = __QSAX(zero, in3);
		in4 = __QSAX(zero, in4);

#endif //       #ifndef ARM_MATH_BIG_ENDIAN

		in1 = ((uint32_t) in1 >> 16) | ((uint32_t) in1 << 16);
		in2 = ((uint32_t) in2 >> 16) | ((uint32_t) in2 << 16);
		in3 = ((uint32_t) in3 >> 16) | ((uint32_t) in3 << 16);
		in4 = ((uint32_t) in4 >> 16) | ((uint32_t) in4 << 16);

		*__SIMD32(pDst)++ = in1;
		*__SIMD32(pDst)++ = in2;
		*__SIMD32(pDst)++ = in3;
		*__SIMD32(pDst)++ = in4;

		/* Decrement the loop counter */
		blkCnt--;
	}

	/* If the numSamples is not a multiple of 4, compute any remaining output samples here.
	 ** No loop unrolling is used. */
	blkCnt = numSamples % 0x4u;

	while(blkCnt > 0u) {
		/* C[0]+jC[1] = A[0]+ j (-1) A[1] */
		/* Calculate Complex Conjugate and then store the results in the destination buffer. */
		*pDst++ = *pSrc++;
		*pDst++ = __SSAT(-*pSrc++, 16);

		/* Decrement the loop counter */
		blkCnt--;
	}

#else

	q15_t in;

	/* Run the below code for Cortex-M0 */

	while(numSamples > 0u) {
		/* realOut + j (imagOut) = realIn+ j (-1) imagIn */
		/* Calculate Complex Conjugate and then store the results in the destination buffer. */
		*pDst++ = *pSrc++;
		in = *pSrc++;
		*pDst++ = (in == (q15_t) 0x8000) ? 0x7fff : -in;

		/* Decrement the loop counter */
		numSamples--;
	}

#endif /* #ifndef ARM_MATH_CM0 */

}

/**
 * @} end of cmplx_conj group
 */
